Floral scent evolution in the genus jaborosa (Solanaceae): Influence of ecological and environmental factors

Floral scent is a key communication channel between plants and pollinators. However,the contributions of environment and phylogeny to floral scent composition remain poorly understood. In this study, we characterized interspecific variation of floral scent composition in the genus Jaborosa Juss. (Solanaceae) and, using an ecological niche modelling approach (ENM), we assessed the environmental variables that exerted the strongest influence on floral scent variation, taking into account pollination mode and phylogenetic relationships. Our results indicate that two major evolutionary themes have emerged: (i) a ?warm Lowland Subtropical nectar-rewarding clade? with large white hawkmoth pollinated flowers that emit fragrances dominated by oxygenated aromatic or sesquiterpenoid volatiles, and (ii) a ?cool-temperate brood-deceptive clade? of largely fly-pollinated species found at high altitudes (Andes) or latitudes (Patagonian Steppe) that emit foul odors including cresol, indole and sulfuric volatiles. The joint consideration of floral scent profiles, pollination mode, and geoclimatic context helped us to disentangle the factors that shaped floral scent evolution across ?pollinator climates? (geographic differences in pollinator abundance or preference). Our findings suggest that the ability of plants in the genus Jaborosa to colonize newly formed habitats during Andean orogeny was associated with striking transitions in flower scent composition that trigger specific odor-driven behaviors in nocturnal hawkmoths and saprophilous fly pollinators.Fil: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Soteras, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Ibañez, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Dötterl, Stefan. Paris-lodron-university Of Salzburg; AustriaFil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Raguso, Robert A.. Cornell University, Dept. Of Neurobiology And Behavior; Estados Unido

Breakdown of species boundaries in Mandevilla: Floral morphological intermediacy, novel fragrances and asymmetric pollen flow

Phenotypic intermediacy is an indicator of putative hybrid origin, and has provided the main clues to discovering hybrid plants in nature. Mandevilla pentlandiana and M. laxa (Apocynaceae) are sister species with clear differences in floral phenotype and associated pollinator guilds: diurnal Hymenoptera and nocturnal hawkmoths, respectively. The presence of individuals with intermediate phenotypes in a wild population raises questions about the roles of visual and olfactory signals (i.e. corolla morphology and floral fragrances) as barriers to interbreeding, and how the breakdown of floral isolation occurs.We examined phenotypic variation in a mixed Mandevilla population analysing the chemical composition of floral fragrances, characterizing floral shape through geometric morphometrics and assessing individual grouping through taxonomically relevant traits and an unsupervised learning algorithm. We quantified the visitation frequencies of floral visitors and tracked their foraging movements using pollen analogues.The presence of morphologically intermediate individuals and pollen analogue movement suggested extensive hybridization between M. laxa and M. pentlandiana, along with asymmetrical rates of backcrossing between these putative hybrids and M. laxa. Floral volatiles from putative hybrid individuals showed a transgressive phenotype, with additional compounds not emitted by either parental species.Our results suggest the presence of a hybrid swarm between sympatric M. pentlandiana and M. laxa and indicate that initial hybridization events between these parental species are rare, but once they occur, visits between putative hybrids and M. laxa are common and facilitate continued introgression.Fil: Rubini Pisano, María Aimé. Universidad Nacional Autónoma de México; México. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: More, Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Cisternas, Mauricio. Jardín Botánico Nacional; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Raguso, Robert A.. Cornell University; Estados UnidosFil: Benitez-Vieyra, Santiago Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

Foraging specificity of Tetralonia (Thygatina) macroceps (Hymenoptera: Apidae: Anthophorinae) on Argyreia cuneata (Convolvulaceae)

Floral specificity is a behavior that evolved due to mutualistic interactions between the plant-pollinator community. Flowers advertise themselves using visual or chemical cues to attract pollinators and gain reproductive success through pollination. Pollinators forage for rewards such as nectar or pollen produced by the flowers. We found that an anthophorid bee, Tetralonia macroceps, foraged specifically on Argyreia cuneata flowers. No visitation was observed on the flowers of A. nervosa though both belong to Convolvulaceae. T. macroceps was the most abundant floral visitor (5.21 bees/flower/5 min) on A. cuneata and did not visit A. nervosa. Mass flowering and narrow tubular flower structure with easy access to pollen in A. cuneata were the traits that accounted for the foraging specificity of T. macroceps. The present study investigates the preference of T. macroceps for the flowers and floral extracts of A. cuneata and A. nervosa. The bee visited 10.16 flowers/5 min of A. cuneata. T. macroceps were highly attracted to the flowers of A. cuneata. No bees were attracted to A. nervosa. The floral abundance of A. cuneata was relatively higher compared to A. nervosa. Pollen analysis of foraging bees of T. macroceps revealed the selective preference towards the pollen of A. cuneata. The highest number of bees preferred the extract of A. cuneata (7.75) compared to A. nervosa (0.50) in the Y-olfactory maze. Floral extract of A. cuneata caused the highest neuronal electroantennogram (EAG) response (1.48 mV) than A. nervosa (0.36 mV). Our preliminary studies indicated the presence of specific volatile organic compounds (VOCs) nonacosane (13.26%), hexatriacontane (12.06%), and beta farnesene (6.19%) observed in A. cuneata were absent in congener A. nervosa

Role of color and odor on the attraction of insect visitors to spring blooming trillium

Plants relying on insects to pollinate flowers attract pollinators through varying floral cues such as unique colors and scents. Pollinators rely on these cues to identify flowers for sources of food such as nectar, pollen, and oils. The goals of this study were to investigate color and odor cues associated with pollinator attraction in populations of Trillium at the Botanical Gardens, Asheville, NC. Insect visitors to the red-scented T. cuneatum and white-non-scented T. grandiflorum were collected using tangle-trap, bottle-traps, transect walk methods. Floral color and odor cues also were investigated using artificial flowers placed among a spring blooming plant community. Artificial flowers colored wine-red, white, or yellow and scented or unscented were covered with transparency film and sprayed with tangle-trap to capture insect visitors. Insects were identified to the level of order and family. Insect visitors to T. cuneatum and T. grandiflorum did not differ and primarily consisted of individuals belonging to the order Diptera, Hymenoptera, and Coleoptera. Diptera were the most abundant visitors consisting of weakly flying dipteran such as Sciaridae and Mycetophilidae. Similar to the real flowers the main visitors to artificial flowers were Diptera, Hymenoptera, and Coleoptera but also included 13 additional orders representing 106 families. Some orders and families collected showed low abundances that could reflect they were being repelled by the floral cues or might not be abundanct in the study area. Overall there was a difference in color (p 0.05). However, when looking at each individual order or family separately, some orders and families were equally distributed for color and odor while others were not, indicating that the importance of floral cues depends on the insect family investigated. For those that were not equally distributed for color, insects were found in greater average percent of individuals on yellow flowers but there was no difference between red and white. For those that were not equally distributed for odor, a greater average percent of individuals were found on scented flowers. Some insects were generalists; visiting all artificial flower treatments randomly, while other insects were more specialized visiting certain color and/or odor treatments in greater numbers indicating a continuum along a gradient of generalized to specialized insect visitors. The ability for plants to attract generalist insect visitors and the ability for insects to visit multiple floral cues might be important where visitation is affected by varying weather conditions and advantageous in the event of environmental change and human altered ecosystems

Molecular and Genetic Regulation of Sensory Quality of Climacteric Fruit

The sensory quality of fruit has become a major criterion in making the purchasing decision by consumers. Breeding programs have mainly been directed, from the post-harvest stand point, towards improving shelf-life. Chance seedlings or mutants with improved agronomic traits and/or extended shelf-life have been used for introgressing the long shelf-life character and eventually improved sensory quality traits in commercial genotypes of apple, melon or tomato. Because the plant hormone ethylene plays a central role in both storability and ripening of climacteric fruit, the generation by biotechnology of ethylene-inhibited fruit has offered a powerful tool to better understand, at the molecular and genetic level, the interrelations between storability and sensory quality. In the melon, inhibition of ethylene synthesis results is a strong inhibition of the synthesis of aroma volatiles while the accumulation of sugars is not affected or is even improved. The softening of the flesh is strongly affected but not abolished. Mid or long shelf-life melons generated by classical breeding present the same behavior. The generation of recombinant inbred lines by crossing a typical climacteric melon (Cantaloupe Charentais of the cantalupensis group) with a non climacteric melon (PI161375 of the agrestis chinensis group) allowed to demonstrate that the climacteric character is conferred by 2 duplicated loci only, which are of great importance for the regulation of storability and sensory quality. Due to the importance of aroma volatiles in sensory quality and to the strong negative correlation between aroma production and ethylene synthesis, we have developed a research program aimed at isolating genes involved in the synthesis of aroma volatiles. We will report on the recent advances in the field with special emphasis on the characterization of genes responsible for the synthesis of esters, a family of compounds crucial for the flavor of many fruit

Preliminary survey of insect diversity and population abundance during flowering and fruiting season in Mangifera odorata (Kuini) orchard, Sintok, Kedah, Malaysia

A preliminary survey of insect population in Kuini (Mangifera odorata) orchard was conducted between February 2016 and May 2016 in MARDI, Sintok, Malaysia. Collection of insects were done using two different methods namely yellow sticky trap (YST) and sweep net. A total of 857 arthropods were collected during flowering season and 1,454 arthropods during fruiting season. Data were analysed using descriptive statistics while mean comparisons were done using t-test. Thysanoptera recorded the highest percentage (31.65%) of total catch during flowering season, while Blattodea and Neuroptera recorded as the lowest with 0.23% respectively. During fruiting season, the highest recorded insect was Diptera (79.92%) while Thysanoptera and Lepidoptera recorded the lowest percentage (0.07%). The Shannon-Weiner diversity index (H’), Simpson Diversity Index (D) and Margalef’s Diversity Index (d) were for insects during flowering season were of 3.01, 0.87 and 12.44 respectively. Conversely, H’, D and d value for insects during fruiting season were 2.61, 0.83 and 7.28 respectively. Results obtained from this study will be used as baseline for future insect pest and biological control related studies

An Evaluation of Hibiscus moscheutos ssp. lasiocarpos and Ipomoea pandurata as host plants of the specialist bee, Ptilothrix bombiformis (Apoidea: Emphorini) and the role of floral scent chemistry in host-selection.

Ptilothrix bombiformis (Hymenoptera: Apoidea) is a specialist bee belonging to the tribe Emphorini. The emphorine phylogeny suggests that Convolvulacea is the ancestral plant family and independent evolutionary host-switches to several unrelated plant families have occurred. The role of floral scent has been well-characterized in pollination systems involving moths, butterflies, bumblebees, and honeybees, but little is known about how specialist bees mediate host selection, or how host-choice evolved in specialist bees. This research investigates the role of floral scent in host selection by P. bombiformis. Ptilothrix bombiformis has traditionally been classified as a Hibiscus (Malvaceae) oligolege. My research shows that it can now be placed into a more detailed dietary classification as an eclectic oligolege because it also collects pure pollen loads from a distantly-related plant, Ipomoea pandurata (Convolvulaceae). Using dynamic headspace sampling and gas chromatography-mass spectrometry, I obtained floral chemical profiles for Hibiscus moscheutos ssp. lasiocarpos and Ipomoea pandurata. Both flowers contain aliphatics, aromatic compounds, monoterpenes, and sesquiterpenes. The host flowers have 14 shared compounds in their floral scent, which may be responsible for the bees\u27 ability to recognize and utilize I. pandurata, a member or the emphorine ancestral host-plant family. Some of these shared compounds are also found in other emphorine host plants and may be responsible for their constraint in host-use

Nocturnal pollination: An overlooked ecosystem service vulnerable to environmental change

© 2020 The Author(s). This is an open access article published by Portland Press Limited on behalf of the Biochemical Society and the Royal Society of Biology and distributed under the Creative Commons Attribution License 4.0 (CC BY). Existing assessments of the ecosystem service of pollination have been largely restricted to diurnal insects, with a particular focus on generalist foragers such as wild and honey bees. As knowledge of how these plant-pollinator systems function, their relevance to food security and biodiversity, and the fragility of these mutually beneficial interactions increases, attention is diverting to other, less well-studied pollinator groups. One such group are those that forage at night. In this review, we document evidence that nocturnal species are providers of pollination services (including pollination of economically valuable and culturally important crops, as well as wild plants of conservation concern), but highlight how little is known about the scale of such services. We discuss the primary mechanisms involved in night-time communication between plants and insect pollen-vectors, including floral scent, visual cues (and associated specialized visual systems), and thermogenic sensitivity (associated with thermogenic flowers). We highlight that these mechanisms are vulnerable to direct and indirect disruption by a range of anthropogenic drivers of environmental change, including air and soil pollution, artificial light at night, and climate change. Lastly, we highlight a number of directions for future research that will be important if nocturnal pollination services are to be fully understood and ultimately conserved

β-Ocimene, a key floral and foliar volatile involved in multiple interactions between plants and other organisms

β-Ocimene is a very common plant volatile released in important amounts from the leaves and flowers of many plant species. This acyclic monoterpene can play several biological functions in plants, by potentially affecting floral visitors and also by mediating defensive responses to herbivory. The ubiquity and high relative abundance of β-ocimene in the floral scents of species from most plant families and from different pollination syndromes (ranging from generalism to specialism) strongly suggest that this terpenoid may play an important role in the attraction of pollinators to flowers. We compiled abundant evidence from published studies that supports β-ocimene as a generalist attractant of a wide spectrum of pollinators. We found no studies testing behavioural responses of pollinators to β-ocimene, that could directly demonstrate or deny the function of β-ocimene in pollinator attraction; but several case studies support that the emissions of β-ocimene in flowers of different species follow marked temporal and spatial patterns of emission, which are typical from floral volatile organic compound (VOC) emissions that are involved in pollinator attraction. Furthermore, important β-ocimene emissions are induced from vegetative plant tissues after herbivory in many species, which have relevant functions in the establishment of tritrophic interactions. We thus conclude that β-ocimene is a key plant volatile with multiple relevant functions in plants, depending on the organ and the time of emission. Experimental behavioural studies on pure β-ocimene conducted with pollinating insects will be necessary to prove the assumptions made here